Cadmium exposures in Canadians raise questions for doctor

The cadmium levels in Canadian adults are similar to those of people in other industrialized countries, according to a new report from Statistics Canada.

Cadmium raised as potential risk factor for kidney disease and osteoporosis

The cadmium levels in Canadian adults are similar to those of people in other industrialized countries, according to a new report from Statistics Canada that raises questions about whether that's too high.

Cadmium, a heavy metal, can cause kidney failure at high levels of exposure and kidney damage, bone loss and other complications in those exposed to moderate amounts over time. Because cadmium can accumulate in the body, exposures should be avoided, health authorities say.

In Wednesday's issue of Health Reports, Statistics Canada researchers measured cadmium levels based on blood and urine samples from 7,095 respondents aged 20 to 79 taken from 2007 to 2011.

Smoking was a huge determinant of cadmium burden in Canadian adults. (Pawel Dwulit/Canadian Press )

"The cadmium levels that we found in the Canadian population through that study were comparable to what is seen in the United States and what's seen in other countries as well, such as Germany," said author Rochelle Garner of Statistics Canada's health analysis division in Ottawa.

When Garner looked at what factors were associated with higher cadmium levels, smoking was top.

Dr. Howard Hu is a dean and professor of environmental health and medicine at the University of Toronto, where he studies toxic metals.

"Unfortunately, there's quite a bit of evidence that cadmium exposures are perhaps increasing," Hu said.

The latest data could help show whether our exposures are on the rise.   

Given that cadmium is difficult for our bodies to excrete, Hu said, it's not clear if we're being exposed to more or less now.

Hu called smoking a huge contributor to our cadmium burden. Whether it's the only source of concern, or if what we eat also adds matters, is hard to tell, he said.

Regardless of how it ends up in our bodies, cadmium's harmful health effects are important to study further.

"Should we be paying attention to cadmium as a risk factor for whatever kinds of kidney disease and osteoporosis are currently being suffered by Canadian adults?" he said. "It's a question in my mind after looking at this data. It's a question that deserves an answer."   

With files from CBC's Amina Zafar


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